Chemistry Experiments

Chemistry Experiments CH-17 Solid liquids and gases To Demonstrate Diffusion in a Liquid Using forceps gently place a few potassium manganate crystals at the bottom of a beaker of water. Observe what happens for a few minutes. Leave your beaker until you next science class. Explain what has happened to the purple particles. Diffusion through gas Set up a gas tube with Ammonia gas on one side using cotton wool and Hydrogen Chloride gas on the other. Makes a white cloud of Ammonium Chloride. CH-18 Solutions and Crystallisation To investigate the solubility of a variety of substances Half fill a test tube with water. Add a spatula of the substance to be tested. Stopper the test tube and shake for 15-20 seconds. Examine, take notes and redo the process. To investigate the effect of temperature on solubility / To grow crystals using copper sulfate. Slowly and with constant stirring add the powdered copper sulfate to the water. Continue until the powder will no longer dissolve but instead settles to the bottom. Heat the beaker to 500C and note what happens to the undissolved copper sulfate. Add more until it won’t dissolve again and heat the beaker to near boiling. Note results and then allow the solution to cool. CH-24 Metals and non-Metals To carry out an experiment to demonstrate that oxygen and water are necessary for rusting Set up three test tubes, one with Calcium chloride and a nail, another with boiled water, a nail and a layer of oil on the water and finally one with a half submerged nail in water and air. Examine each test tube after one week or so. CH-26 Acids and Bases To titrate hydrochloric acid (HCL) against sodium hydroxide (NaOH) and prepare a sample of sodium chloride (NaCl) Measure 25cm3 of sodium hydroxide into a conical flask with 3-4 drops of indicator. Slowly add the acid from the burette to the flask until the indicator changes colour, note volume of acid. Repeat this experiment and average the amount of acid used. Now don’t use indicator and add that amount of acid. Take the titration and evaporate it, leaving you with sodium chloride. Investigate the reaction between zinc and hydrochloric acid and test for hydrogen Set up apparatus. Add the hydrochloric acid. Take the test tube and stopper it while under water. Then test for hydrogen. CH-27 The Atmosphere To prepare a sample of oxygen gas and examine its properties Manganese dioxide, hydrogen peroxide. Product: Magnesium oxide-Base Note smell, colour and test PH. Place a glowing splint into a jar of oxygen. Heat a combustion spoon of carbon and place it in the gas, testing for CO2. Burn magnesium in the gas jar. Test the product with litmus. To prepare CO2 and examine its properties Hydrochloric acid, calcium carbonate. Note smell, colour and test PH. Place into limewater. Pour it on a candle. CH-28 Water To electrolyse water Invert two test tubes over two electrodes of carbon or platinum. Add water and add dilute sulfuric acid to increase conductivity. CH-29 Water Hardness To test water for hardness Place equal volumes of water from different places in 4 test tubes. Add a bit of soap flakes and shake for 10 seconds. If it doesn’t lather then try again with more soap flakes and count how many times it takes. Formulas Lithium + water → Lithium hydroxide + hydrogen Lithium + oxygen → Lithium oxide Same for sodium. Fossil fuel + oxygen → Carbon dioxide + water Acid + base → Salt + water Hydrochloric acid + Sodium hydroxide → Sodium chloride + water HCl + naOH → NaCl + H2O Acid + carbonate → Salt + water + carbon dioxide Acid + metal → Salt + hydrogen Zinc + hydrochloric acid → Zinc chloride + hydrogen Zn + 2HCl → ZnCl2 + H2 Manganese DioxideHydrogen peroxide → Oxygen + water 2H2O2 MnO2 O2 + H2OHydrochloric acid + calcium carbonate → Calcium chloride + water + carbon dioxide 2HCl + CaCO3 → CaCl2 + H2O + CO2 Calcium hydroxide + carbon dioxide → Calcium carbonate + water Ca(OH)2 + CO2 → CaCO3 + H2O 2H2O → 2H2 + O2 -Calcium ions + soap → Scum